Failed insulation on Fan

[Jacko]

hi guys,

Could someone please tell me why the ‘insulation’ has failed on this pat test please? I thought over 1MOhm was ok?

The test is on a fan in a dental surgery.

Thanks

 

[westward10]

The requirements for PATests are 1.0 Meg ohm for a Class 1 appliance and 2.0 Meg ohm for a Class II appliance. So if it was Class II it is below the required minimum.

 

[Jacko]

Thank you got the quick response.

I haven’t done any PAT testing, does this men that the flex need to be changed or that the fan unit is faulty?

Thanks again

 

[westward10]

Well it could be either you need to narrow it down, the three elements which could be causing it are likely to be plug, cord or the fan unit assuming there are no other parts to it.

 

[Jacko]

Ok, the certificate says that the plug and flex both ‘pass’.

Looks like the fan itself

 

[westward10]

That could just be a visual check as the insulation test would include all parts together and not a separate check on each. Is it a Class I or Class II fan.

 

[Jacko]

I’m not sure, I’m am starting PAT testing training soon so have been given some certificates to look at in advance.

Must be class II if it’s failed with those results?

 

[westward10]

I would assume so but a cautious or experienced person may view the reading as warranting attention for a Class I appliance.

 

[telectrix]

i.m confused. appliance IR testing is carried out L/N -E. where is the E on a classII appliance?

 

[Jacko]

Sorry?

So you only do IR while pat testing on a class I appliance?

 

[westward10]

i.m confused. appliance IR testing is carried out L/N -E. where is the E on a classII appliance?

Class II appliances may have exposed metal parts which require an IR test.

 

[pirate]

As Westward says, if there are exposed metal parts, then they will require an IR test...and obviously if there are none then no test because a) you don't need one, and b) you can't...
Fans in particular, as has been mentioned in these forums before, are awkward beggars to test. How far do you go with "finding" exposed metal parts? If you have to dismantle the cage to find some metal to touch then that is going too far imo...but if you "could" theoretically touch an exposed metal part, say around the middle of the rotor, with a finger but not using any tools, I think it is fair to take the safest route and test it with your probe...why wouldn't you? as I say, fans are often tricky due to their widely ranging types of construction...I'm not a fan.

 

[westward10]

Many desk or standard fans are Class I but the metal parts which are earthed tend to be within the motor housing and not open to touch. A good example of a metal cased Class II appliance could be a DVD player and the IR test should be carried out with the earth bond test lead connected to the casing.